Back Up Parking Aid Issue

[gulfman]

I keep getting the message to " Check Backup aid" when I put the transmission in reverse. I took it to my ford dealer and their computer got an error code C1983. They said I needed a new Parking Aid Module for $ 450.00. I said to forget it. I went to a salvage yard and tried 2 Parking Aid Modules. The numbers all matched with the original. It made no difference. The chances of 2 modules being bad is slim.

The Back Up Aid works fine when the temperature is 40 degrees or below. Above 40 degrees inside the vehicle, it then gives the same message "Check Backup Aid". Does anyone have any ideas what could be causing this problem?
Bob

 

[bedrck46]

That code means RADAR SENSOR MALFUNCTION depending on if you have a early or late production Expedition you will have either 3 or 4 sensors in the rear. Only the early production had the 3 sensors and the one in the middle is the radar sensor Maybe you can return to the salvage yard and remove the radar sensor and try that.

 

[gulfman]

That code means RADAR SENSOR MALFUNCTION depending on if you have a early or late production Expedition you will have either 3 or 4 sensors in the rear. Only the early production had the 3 sensors and the one in the middle is the radar sensor Maybe you can return to the salvage yard and remove the radar sensor and try that.

Thanks bedrck46. I'll give it a try.
Bob

 

[bedrck46]

let me know how you make out

 

[gulfman]

I will try a radar unit from the salvage yard as soon as the temperature gets above 45 degrees. Below that temperature, the backup aid works fine. Very weird.
More to come!
Bob

 

[gborree]

Where is that radar sensor located? Thanks!

 

[gulfman]

The radar is located in the center of the bumper. If you look behind the trailer hitch directly back of the receiver, you should see the wire that goes to the unit. To get to the radar unit, you have to remove the bumper. Try to get the fault code from a body chasse scanner. The OBDII will not give you a chasse code. The code for the radar was C1983. There is also a backup aid module on driver side rear panel under the plastic tray. That is why the correct code is important.

 

[MasterEngineer]

Has anyone been able to resolve this? Just like Gulfman, I also went to the salvage yard and pulled two PAM's (same part number: 2L1T-15T850-AJ), which made no difference. However, because I live in Florida, it doesn't get below 40 degrees very often, so I don't know if my system would work in the cold.

Mechanic friend of mine pulled a C1983 DTC from the system before I tried swapping the PAM's. And while C1983 does mean "Radar Sensor Malfunction", TSB 06-25-13 suggests replacing the PAM with a new one (P/N: 4L7Z-15K866-AB).

Wires all seemed to be connected properly, so I'm wondering if it's either the ultrasonic sensors (the two outboard sensors) or the radar sensor (center sensor above the hitch).

Any input would be much appreciated. Thanks in advance...

 

[gulfman]

Temperature should not have anything to do with it. Mine was the radar unit Code(C1983) located in the center above the hitch. You can see the wiring from the back but it must be removed from the front. The removal procedure for the bumper plastic should be on Google or You Tube.

 

[MasterEngineer]

I went to the salvage yard today and pulled two radar sensors. Unfortunately, they didn't fix my problem. One of them was effectively useless (no change from original unit), and the other was slightly less useless, as I could occasionally get the parking aid system to operate long enough to hear the clicking from each sensor (but not long enough to hear them at the same time...). However, after I finished installing the bumper cover (I was doing a "dry-fit" during testing), my status went back to the same, where I could never get the parking aid system to operate - it would go straight to "Check Backup Aid".

I left the slightly less useless one installed...

 

[gulfman]

Did you try the reprograming instructions listed in the TSB.

 

[MasterEngineer]

I did, but no success

(assuming I did it right - the only part of the reprogramming steps I was unsure of was the end where you cycle the key off then on. Do you come to a stop in Drive (D), then turn the car off (still in Drive), then switch the key to on (still in Drive), then after the key/car is switched on, put the car in Park, then start the car and proceed with the steps? If so, then I successfully reprogrammed the PAM with no change. If I messed up the steps, then I did not successfully reprogram the PAM.)

 

[gulfman]

To make a long story short, at the end of me fooling around with the replacing modules from the junk yard which made no difference, the local dealer replaced the radar module ( his diagnostic tools got the code C1983) and I believe he said the mechanic had to drive the vehicle around to reprogram it. I hope this helps you.
I'm not a mechanic (just a hacker) who went through a lot of crap before I finally got it fixed. The Ford dealer not knowing I has tried 2 modules before I took it to them, tried to charge me for both a module and a radar unit. I asked to see the old radar unit and was told they lost it after I had pacifically told them I wanted the old part before that started the job. After a discussion with the service manger!!!, I was only charged for the radar unit.

 

[MasterEngineer]

Oh man, that's quite an experience!

I'm trying to avoid the dealership at all costs, but the mechanic who pulled the code for free is a few hours away, and I just don't have the time to make the trip.

It's just frustrating because I've replaced both the PAM and radar sensors with two units from the salvage yard, and I find it hard to believe there isn't a working unit in that lot of parts

 

[gulfman]

I would try to reprogram the module a couple of times as per the TBS. I don't know what else to tell you. If that does not work, try googling the internet and see what comes up. I share your concerns about the going to a Ford dealer unless you know someone there and trust them. I no longer trust my dealer's service department who is only a couple miles away. Once trust is lost, it is very difficult to get back. In the past, I had purchased numerous company vehicles from them and gave them thousands of dollars in repair work on the company cars I drove in my job. Good luck!
Let us know how you make out.

 

[MasterEngineer]

Thanks for the advice, gulfman. I'll keep at it and let everyone know how the rest of this story unfolds.